they still offer the Rockster? They used one in a really bad Bond film, eek!
<- expert? no.
<- afficianado? yes.
I think you're asking about boxer engines??
But where do the Brits come in? BMW is Bavarian, you know German. Brits have bad teeth and pasty skin, Germans are thin and angry.
Anywhoo, before the numbskulls get in here and start bashing for bashing's sake let's talk BMW. BMW has its origins in aircraft design however the Versailles Peace Treaty banned aircraft engine production in Germany in 1919. BMW was already using the Boxer (flat opposed) engines and needed something else to do, so they parlayed their experience into building motorcycle engines in 1920 and began supplying engines to Victoria (a bike manufacturer) in 1921.
The boxer engine has gone through reconfigurations over the years but has remained essentially the same. It is a tried and true proven design.
The 800cc bikes you were looking at are not boxer engines. BMW denotes boxer engined bikes with the first letter "R" in the bike name, example R1200GS, R1150GS, R1200S, etc. "K" bikes are I4 engines and "F" bikes are 800 twins or 650 thumpers.
Reliability? I will only speak from what I know from my R1200GS... approaching 12000 miles in 2 years it has run flawlessly. I will be taking it in for a 12000 mile service and the valves will be adjusted and the throttle bodies synched as well as the fluids changed and brakes inspected & R&R'd if needed.
Some BMWs are quite simple with very little to break, others are very complex with active engine monitoring systems and safety features. My bike has power linked ABS brakes, it applies braking force to both the front and rear wheels by activating only the hand lever. I've tested the ABS and it works as described by BMW. And yes, believe it or not, my +500lb adventurebike WILL stop shorter than any sportbike I've ever ridden (and I've ridden most of them).
Money? Yep, nothing BMW affiliated is cheap. But there's no reason you can't put 80,000 miles on a well serviced & maintained R1200GS and still sell it for money instead of begging someone to come pick it up.
Yes, I'd buy another one tomorrow if I needed to. Your dealer sucked, sorry. My dealer rocks and is far and away better than any of my japanese bike dealers.
About what else could I go into specifics?